Current Advancements of Orally Administered Nanomedicine: Disease Diagnosis and Therapy via Targeted Delivery.

With advances in nanotechnology, nanomedicines that combine diagnostic and therapeutic functions have emerged, offering advantages such as early, precise diagnosis and more reliable therapeutic outcomes than conventional treatments. Despite these benefits, most nanomedicines require intravenous or other invasive administration routes, leading to safety and patient compliance concerns that hinder clinical translation. Oral delivery represents an ideal drug administration method due to its convenience and the protective barrier provided by the gastrointestinal tract, which enhances safety and compliance. However, challenges such as low drug solubility, limited permeability of the gastrointestinal barrier, and the harsh acid-base and enzymatic environment of the gastrointestinal tract significantly impact the efficacy and application of oral nanomedicines. Additionally, reduced bioavailability resulting from first-pass hepatic metabolism after gastrointestinal absorption through the venous plexus presents a major technical obstacle for orally administered nanomedicines. This review introduces design strategies for oral nanomedicines using a function-oriented approach and summarizes the characteristics of various nanomedicine types based on structural similarities and differences. Several representative oral nanomedicines developed in recent years are highlighted, with a focus on their applications to specific diseases. The review also discusses the potential and current limitations of oral nanomedicines that must be addressed to facilitate future clinical translation. The primary objective is to provide a comprehensive analysis of oral drug administration from multiple perspectives and to offer valuable insights for clinical application.